AB1109 EVALUATION OF THE POTENTIAL INDUCTION OF AUTOANTIBODIES AFTER THE ANTI-SARS-COV2-VACCINATION IN A COHORT OF PATIENTS WITH TRIPLE POSITIVITY FOR ANTIPHOSPHOLIPID ANTIBODIES
Authors: P. Semeraro, S. Bertocchi, S. Piantoni, L. Andreoli, F. Franceschini, E. Garrafa, A. Tincani
Journal: Annals of the Rheumatic Diseases (2022)

Background Anti-SARS-CoV2 vaccines showed a good efficacy in prevention of severe COVID-19 1 . Their potential in induction of autoantibodies (abs) has not been well established 1 . One recent study demonstrated an increase of abs’ titre after anti-SARS-CoV2 vaccination only in patients with already pre-existing positivity 2 . Objectives To evaluate the potential induction of abs after anti-SARS-CoV2 vaccination in a triple positive antiphospholipid antibodies (aPL) cohort. Methods 18 subjects were enrolled [M/F= 17/1; median age=52 years; 5 Primary Antiphospholipid Syndrome (PAPS), 5 Systemic Lupus Erythematosus (SLE) with associated APS and 8 aPL carriers (1 Behçet Disease, 1 SLE, 4 Undifferentiated Connective Tissue Disease, 2 with no diagnosis of systemic autoimmune disease)]. Serum samples were collected before the first (T0) and at least one month after the second administration (T1) of the anti-SARS-CoV2 vaccine (16 BNT162b2, 1 mRNA-1273, 1 Gam-COVID-Vac). A wide panel of abs were evaluated through routinely methods. Results None developed any additional sign of autoimmune diseases upon vaccination. Patients majority did not display any new autoantibody positivity (Table 1). Changes were observed in 3 patients: 1) one aPL carrier patient who was antinuclear antibodies (ANA) negative at T0 was found to be ANA positive at T1 [negative anti-double stranded DNA and anti-extractable nuclear antigen (ENA)]; this patient was actually ANA positive in her clinical history; 2) one aPL carrier patient affected by SLE, who was IgM and IgG aCL and IgG aB2GPI positive at T0, turned positive for IgM and IgA aB2GPI; 3) one aPL carrier patient affected by Behçet Disease, who was positive for IgM aCL and for IgM aB2GPI at T0, turned positive for IgA aCL and IgA aB2GPI. Table 1. Autoantibodies’ titre pre (T0) and post (T1) anti-SARS-CoV2 vaccination. Autoantibodies Level at T0 Level at T1 p-value* Patients positive at T0 Patients positive at T1 p-value° Anti-dsDNA 28.7 (21.8-64.5) 25.8 (15.9-68.5) 0.163 7/18 (38.9%) 6/18 (33.3%) 0.729 (n.v. &lt;27 IU/ml ) aCL IgG 88.1 (27.1-218.9) 68.2 (18.8-181.3) 0.118 15/18 (83.3%) 13/18 (72.2%) 0.691 (n.v. &lt;20 CU ) aCL IgG 11.9 (11.2-77.2) 11.2 (11.2-24.5) 0.432 9/18 (50%) 7/18 (38.9%) 0.502 (n.v. &lt;12 IU/ml ) aCL IgM 20.8 (5.9-35.9) 8.9 (3.3-21.6) 0.006 9/18 (50%) 5/18 (27.8%) 0.171 (n.v. &lt;20 CU ) aCL IgM 30.4 (18.1-170.8) 23.8 (11.2-82.3) 0.029 14/18 (77.8%) 12/18 (66.7%) 0.457 (n.v. &lt;12 IU/ml ) aCL IgA 11.7 (11.2-30.9) 11.2 (11.2-17.6) 0.029 8/18 (44.4%) 6/18 (33.3%) 0.494 (n.v. &lt;12 IU/ml ) aβ2GPI IgG 230.4 (110.1-971.1) 242.3 (33.7-652.9) 0.083 16/18 (88.9%) 14/18 (77.8%) 0.658 (n.v. &lt;20 CU ) aβ2GPI IgG 9.3 (9.3-128.1) 19.4 (9.3-126.9) 0.844 8/18 (44.4%) 9/18 (50%) 0.738 (n.v. &lt;20 IU/ml ) aβ2GPI IgM 16.9 (3.6-51.3) 6.8 (1.5-23.1) 0.041 7/18 (38.9%) 5/18 (27.8%) 0.480 (n.v. &lt;20 CU ) aβ2GPI IgM 19.8 (11.1-78.8) 9.9 (9.3-52.4) 0.109 8/18 (44.4%) 7/18 (38.9) 0.735 (n.v. &lt;20 IU/ml ) aβ2GPI IgA 20.8 (9.3-39.9) 9.3 (9.3-37.8) 0.080 10/18 (55.6%) 7/18 (38.9%) 0.317 (n.v. &lt;20 IU/ml ) Antiphospholipid antibodies were determined with chemiluminescence (CU) and home-made ELISA (IU/ml) methods of detection. Pre and post-vaccine values are expressed as median (IQR). In bold, statistically significant comparisons. *Wilcoxon signed-rank test for paired variables was applied. °Chi-square test or Fisher’s exact test were applied. dsDNA=double-stranded DNA; aCL: anti-cardiolipin; aβ2GPI: anti-beta2-glycoprotein I; n.v.: normal value. All emerging aPL were low titre. None of the patients displayed raising aPL titres from low to medium-high. Conclusion Anti-SARS-CoV2 vaccination did not induce any clinical signs of autoimmunity in a cohort of patients with triple aPL positivity. Serology for autoantibodies remained stable in the majority of patients. Few patients experienced the emergence of low titre aPL, possibly as an expected inter-assay variation rather than an evolving “serological flare”. References [1]Ishay Y et al. Int Immunopharmacol. 2021; [2]Thurm C et al. medRxiv 2021. Disclosure of Interests None declared